ICs Convert 1.8 To 5.5 Vdc To Vac Needed To Drive EL Lamps

Capable of operating directly from 2-cell alkaline/NiCd/NiMH or 1-cell Li Ion batteries, the MIC4826/4827 ICs are designed to convert a 1.8 to 5.5 Vdc voltage from the batteries to the high ac voltage needed to drive electroluminescent (EL) lamps used for backlighting LCDs and keypads found in products such as cell phones and PDAs. The MIC4826 generates 160V and MIC4827 180V peak-to-peak ac output voltage, with the latter intended for use where maximum EL brightness is needed. The ICs make the Vdc-to-Vac conversion by employing both a boost and an H-bridge lamp driver stage, with both devices also permitting EL lamp frequency and boost converter frequency to be independently adjusted. The EL lamp drivers also feature 0.1 µA shutdown current and a -40¡C to +85¡C operating temperature range. In 8-pin MSOP-8 packages, the MIC4826 costs $1.18 each/1,000 and the MIC4827, $1.28. For more details, call Tony Grizelj at MICREL INC., San Jose, CA. (408) 944-0800.